This invention relates in general to a conveyor system for sequentially moving a plurality of workstations through a work area.
Workstations within the scope of this invention include platforms carrying tools for performing any type of work on a workpiece. Several conveyors for moving various types of workstations are known. One type of workstation may cut a continuous moving workpiece downstream from a rolling station where the workpiece is formed. Such workstations move at a speed which approximates the speed of the workpiece, and are used to cut continuously formed materials such as rods, pipes, bar stock, tubing and elongate materials for making items such as pencils or cigarettes.
In some prior art conveyors, reciprocating workstation accelerators accelerate the workstation to a speed where it approximates the speed of the workpiece. The workstation then clamps and performs work on the workpiece, and reciprocates back to a start position, awaiting the start of the next acceleration. These systems are deficient in some regards. The return reciprocation and the time necessary to accelerate the workstation from a stopped position, to the workpiece speed, requires a minimum time between sequential working of the workpiece. These factors limit the frequency with which the workstations may work on the workpiece. When the work is cutting this also limits the ability to cut small portions of the moving workpiece.
Conveyors have been developed which include two such reciprocating accelerators spaced on opposed lateral sides of the workpiece. Although such systems reduce the necessary time between cuts, they do not completely eliminate the restriction.
Other known systems may move a plurality of workstations by a continuous member such as a chain. The chain typically has a plurality of workstations at fixed locations such that they work sequentially on a workpiece. Such systems are inflexible and do not allow an operator to control the spacing between the sequential workstations.
Systems are known in the prior art where a plurality of members are moved about a track-like structure, and the distance between the plurality of work performing members may be controlled. Such systems have not been used to work sequentially on a workpiece, however, and thus do not address the above-discussed problems.